package com.ipe.common.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.RandomStringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class VerificationCodeUtil {
	private static final Logger LOGGER = LoggerFactory
			.getLogger(VerificationCodeUtil.class);

	private static final int width = 70;
	private static final int height = 27;

	public synchronized static void createCode(HttpServletRequest request,HttpServletResponse response) {
		response.setContentType("images/jpeg");
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		ServletOutputStream out=null;
		try {
			String s = RandomStringUtils.random(4, true, true);
			request.getSession().setAttribute("captcha", s);
			out = response.getOutputStream();
			BufferedImage image = new BufferedImage(width, height,
					BufferedImage.TYPE_INT_RGB);
			Graphics g = image.getGraphics();
			// 设定背景色
			g.setColor(getRandColor(200, 250));
			g.fillRect(0, 0, width, height);
			// 设定字体
			Font mFont = new Font("黑体", Font.BOLD, 21);// 设置字体
			g.setFont(mFont);

			// 画边框
			g.setColor(Color.BLACK);
			// g.drawRect(0, 0, width - 1, height - 1);

			// 随机产生干扰线，使图象中的认证码不易被其它程序探测到
			g.setColor(getRandColor(160, 200));
			// 生成随机类
			Random random = new Random();
			for (int i = 0; i < 155; i++) {
				int x2 = random.nextInt(width);
				int y2 = random.nextInt(height);
				int x3 = random.nextInt(12);
				int y3 = random.nextInt(12);
				g.drawLine(x2, y2, x2 + x3, y2 + y3);
			}

			// 将认证码显示到图象中
			g.setColor(new Color(20 + random.nextInt(110), 20 + random
					.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(s, 2, 16);

			// 图象生效
			g.dispose();
			// 输出图象到页面
			ImageIO.write((BufferedImage) image, "JPEG", out);
		} catch (Exception e) {
			LOGGER.error("createCode error {}", e);
		} finally{
			if(out!=null){
				try {
					response.flushBuffer();
					out.flush();
					out.close();
					out=null;
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	private static Color getRandColor(int fc, int bc) { // 给定范围获得随机颜色
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}
}
